From: "Stephen C. Tweedie" <sct@redhat.com>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
Andre Hedrick <andre@linux-ide.org>,
Douglas Gilbert <dougg@torque.net>,
linux-kernel@vger.kernel.org, Stephen Tweedie <sct@redhat.com>
Subject: Re: scsi vs ide performance on fsync's
Date: Wed, 7 Mar 2001 13:48:24 +0000 [thread overview]
Message-ID: <20010307134824.A3715@redhat.com> (raw)
In-Reply-To: <E14aGHY-0000Yc-00@the-village.bc.nu> <Pine.LNX.4.10.10103061042250.1989-100000@penguin.transmeta.com>
In-Reply-To: <Pine.LNX.4.10.10103061042250.1989-100000@penguin.transmeta.com>; from torvalds@transmeta.com on Tue, Mar 06, 2001 at 10:44:34AM -0800
Hi,
On Tue, Mar 06, 2001 at 10:44:34AM -0800, Linus Torvalds wrote:
> On Tue, 6 Mar 2001, Alan Cox wrote:
> > You want a write barrier. Write buffering (at least for short intervals) in
> > the drive is very sensible. The kernel needs to able to send drivers a write
> > barrier which will not be completed with outstanding commands before the
> > barrier.
>
> But Alan is right - we needs a "sync" command or something. I don't know
> if IDE has one (it already might, for all I know).
Sync and barrier are very different models. With barriers we can
enforce some elemnt of write ordering without actually waiting for the
IOs to complete; with sync, we're explicitly asking to be told when
the data has become persistant. We can make use of both of these.
SCSI certainly lets us do both of these operations independently. IDE
has the sync/flush command afaik, but I'm not sure whether the IDE
tagged command stuff has the equivalent of SCSI's ordered tag bits.
Andre?
--Stephen
next prev parent reply other threads:[~2001-03-07 13:51 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-03-06 5:27 scsi vs ide performance on fsync's Douglas Gilbert
2001-03-06 5:45 ` Linus Torvalds
2001-03-06 7:12 ` Andre Hedrick
2001-03-06 12:09 ` Alan Cox
2001-03-06 18:44 ` Linus Torvalds
2001-03-07 13:48 ` Stephen C. Tweedie [this message]
2001-03-07 14:13 ` Jens Axboe
2001-03-12 18:50 ` Andre Hedrick
2001-03-06 13:50 ` Mike Black
2001-03-06 16:02 ` Jeremy Hansen
2001-03-07 18:27 ` Jeremy Hansen
2001-03-07 18:36 ` Linus Torvalds
2001-03-08 11:06 ` Stephen C. Tweedie
2001-03-06 16:57 ` Jonathan Morton
2001-03-06 6:43 ` Jonathan Morton
2001-03-06 13:03 ` dean gaudet
2001-03-06 13:15 ` dean gaudet
2001-03-06 13:45 ` Jonathan Morton
[not found] <1epyyz1.etswlv1kmicnqM%smurf@noris.de>
2001-03-09 6:59 ` Matthias Urlichs
2001-03-09 11:51 ` Jens Axboe
2001-03-09 14:26 ` Matthias Urlichs
-- strict thread matches above, loose matches on Subject: below --
2001-03-07 12:47 David Balazic
2001-03-06 19:42 David Balazic
2001-03-06 20:37 ` Jens Axboe
2001-03-07 13:51 ` Stephen C. Tweedie
2001-03-07 14:12 ` Jens Axboe
2001-03-07 15:05 ` Stephen C. Tweedie
2001-03-07 18:51 ` Jens Axboe
2001-03-07 19:10 ` Stephen C. Tweedie
2001-03-07 20:15 ` Jens Axboe
2001-03-07 20:56 ` Stephen C. Tweedie
2001-03-07 20:59 ` Jens Axboe
2001-03-08 15:45 ` Chris Mason
2001-03-06 17:14 David Balazic
2001-03-06 17:46 ` Gregory Maxwell
2001-03-06 18:23 ` Jonathan Morton
2001-03-06 23:27 ` Mark Hahn
[not found] <Pine.LNX.4.33L2.0103021033190.6176-200000@srv2.ecropolis.com>
[not found] ` <054201c0a33d$55ee5870$e1de11cc@csihq.com>
2001-03-04 20:10 ` Douglas Gilbert
2001-03-04 21:28 ` Ishikawa
2001-03-06 0:11 ` Douglas Gilbert
2001-03-02 17:42 Jeremy Hansen
2001-03-02 18:39 ` Steve Lord
2001-03-02 19:17 ` Chris Mason
2001-03-02 19:25 ` Steve Lord
2001-03-02 19:27 ` Jeremy Hansen
2001-03-02 19:38 ` Chris Mason
2001-03-02 19:41 ` Steve Lord
2001-03-05 13:23 ` Andi Kleen
2001-03-02 19:25 ` Andre Hedrick
2001-03-03 1:55 ` Dan Hollis
2001-03-02 20:56 ` Linus Torvalds
2001-03-06 2:13 ` Jeremy Hansen
2001-03-06 2:25 ` Linus Torvalds
2001-03-06 3:30 ` Jonathan Morton
2001-03-06 4:05 ` Linus Torvalds
2001-03-06 7:03 ` Andre Hedrick
2001-03-06 8:24 ` Jonathan Morton
2001-03-06 12:22 ` Rik van Riel
2001-03-06 14:08 ` Jonathan Morton
2001-03-07 16:50 ` Pavel Machek
2001-03-06 19:41 ` Andre Hedrick
2001-03-07 5:25 ` Jonathan Morton
2001-03-07 6:58 ` Andre Hedrick
2001-03-09 11:39 ` Jonathan Morton
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